1. Field of the Invention
The invention lies in the field of processing or the transport of objects, in particular of printed products. It relates to a device and to a method according to the preambles of the claims, with which device or with which method the objects are processed with acting elements moved along a closed revolving path, and the distance of the acting elements is to be changed, for example, for adaptation to different formats or transfer locations.
2. Description of Related Art
With the processing of continuously conveyed objects, the distance of the tools used for processing must often be adapted to the distance of the objects in the conveyor flow to be supplied and/or to be released. Various solutions are known for this:
Processing devices and transport devices for printed products are known from EP-A 0 606 55, EP-A 0 606 549 and EP-A 0 606 555, with which tools, e.g. grippers or stitching modules, are moved along an essentially circular path, and with which the distance of the tools changes during their movement along the path. The distance change is achieved by way of the tools being arranged at the outer end of levers, and the orientation of the levers being changed relative to the radial direction by way of cooperation with suitable control elements/guide elements during the revolving.
A similar device which serves as a transfer wheel for singularising continuously conveyed objects, is known from EP-A 1 736 427. Here, the objects are received by grippers at a receiver location and are moved along a circular-arc-like revolving path up to a release location, where they are deposited onto a conveyor belt. The distance of the grippers along the path increases from the receiver location to the release location. For this, the grippers are arranged at the outer end of the levers, whose inner ends are articulated on a circular drive disk and whose orientation with respect to the drive disk is fixed in dependence on the position of the lever along the peripheral path, by guide elements which cooperate with the levers and run along a circular path which is eccentric with respect to the drive disk.
A device for processing, in particular for welding or cutting objects conveyed one after the other in a continuous manner, is known from WO 2007/147269, with which at least two tools are moved with variable speeds along a closed revolving path, in order to realise different processing distances. For this, two drives for example are provided. One of the drives moves the tools at a processing speed which is adapted to the conveying speed, and the other drive moves these at a return speed, which is adapted to the distances to be created. Alternatively, WO 2007/147269 suggests the selective coupling or decoupling of the tools on a continuously operating drive, and thus, of realising different processing distances.
For many applications, it is necessary to change the distance between two tools, e.g. in order to adapt the processing to the current product length or in order to change the distance of two products held by the tools.
Although with the transfer wheel according to EP-A 1 736 427, the distance of two grippers along the revolving path changes, the distance of two consecutive grippers at any reference point along the revolving path is constant. The distance, thus, depends only on the position of the gripper along the revolving path. A format change is only possible by way of different adaptations.
The different drives with the device according to WO 2007/147269, although permitting an adaptation of the processing distance, are however mechanically complicated and expensive in maintenance.
It is therefore the object of the invention, to specify a simple solution for changing the distance of the tools with regard to a processing device.